If you know a deposit was paid but cannot identify the protection scheme, start by turning the broad concern into a set of smaller checks.
Questions worth asking
- What name or reference appears in the tenancy paperwork?
- Do old emails or messages mention a scheme or certificate?
- Which details did you use when searching your records?
- Are the tenancy, payment and correspondence dates recorded together?
Different names, addresses or reference formats can make a record harder to recognise. Note the variations you find rather than assuming they refer to different matters.